MBWEII (White Light) - Drive B broken - replaced with new drive but it won't auto mirror

I am testing my MBWE II  (White Light) before trusting it.


Drive B has failed - take it out and throw it away.

Insert replacement drive (C?)

However drive C has previously been used (in the MBWEII for testing mirroring) so has old files and old partitioning and so the MBWEII shows the HDD status as:

HDD1 (A) = Good

HDD2 © = Unassigned

So when following the replacement procedure in the manual, it doesn’t automatically mirror data on A to C.

I think I need to completely wipe and de-partition drive C before inserting but there is no obvious way of doing this.

What should I do so that when I insert drive ‘C’, MBWEII automatically mirrors the data from drive A to drive C

Thanks in advance,